In many areas, such as in multimode mobile telephones, a linear signal amplification with high power efficiency is needed. One option for achieving a linear signal amplification is to linearize a non-linear power amplifier which thus exhibits a non-linear characteristic curve, by injecting a predistorted signal. This amplification process is known as predistortion. The combination of the predistorted injected signal and the non-linear characteristic amplifier curve produces overall a linear characteristic curve of the power amplifier and thereby a linear signal amplification.
A problem with this method of amplification is that only the signal quality is improved with particular regard to linearity. The output power and the efficiency have not been able to be increased thus far with this linear signal amplification by the predistortion.